When computer users wish to collaborate, the current state of the art is to provide a “collaborative application” mediating the interactions between users. The collaborative application limits what each user can do, in part to prevent one user from corrupting the work of another. But these limits may be intolerable for some collaborative tasks, such as debugging computer software. The current state of the art for such collaborative tasks is to set up a computer dedicated to this task, and back it up frequently so that corruption can be recovered from.
Virtual machine monitor (VMM) software such as VMWare Workstation, available from VMWare of Palo Alto, Calif. runs as an application program on various operating systems, such as Linux and Microsoft Windows®, and creates virtual machines. A virtual machine emulates a hardware processor, including the processing unit, memory, storage devices and networking. Virtual machine technology is now practical for personal computing due to advances in system hardware and software. Processor, memory and storage speed have increased significantly, allowing virtual machines to be used for personal computing without a significant impact on normal productivity. Memory and disk storage have decreased significantly in cost, making virtual machines more attractive.
A virtual machine is said to be isolated from the personal computer it runs on, because it may not change the state of that personal computer, except in certain, very controlled ways. This isolation makes virtual machines ideal for computations which cannot be trusted, such as computations which may be performed by many collaborators in a shared computing environment.
Virtual machines may be shared by multiple users if a multiple user operating system is installed in them. Examples of multiple user operating systems include Linux and Microsoft's Windows Server 2003. Shared virtual machines can support collaboration among their users, by permitting users to share files, execute programs and use collaboration applications, such as Web Servers running Wiki software. Wiki software is described in the web pages of wiki.org and in the book “The Wiki Way: Collaboration and Sharing on the Internet,” published by Addison-Wesley Professional, 2001.
Thus, the advent of virtual machines has provided advantages for end users. Nonetheless, this technology has presented several drawbacks. In particular, the proliferation of virtual systems in computing environments presents drawbacks for users who now have to access two or more virtual machine to perform productivity tasks. This can be particularly burdensome since a user may need to switch between or among multiple graphical user interfaces to perform tasks. For example, in one possible implementation in accordance with the prior art, an end user would have to bring a desktop-like operating environment associated with each particular virtual machine into focus every time the user switches from performing tasks in the operating environment associated with one virtual machine to the operating environment associated with another virtual machine.
This can be even more burdensome if tasks are to be performed using both private and collaborative virtual machines at various points. In collaborative virtual machines, authorized changes made to, for example, software under development, would be spawned to all collaborators immediately. A software developer may wish to develop, test and debug a portion of the software in his own private virtual machine before publishing it to collaborators in the collaborative virtual machine. Accordingly, in computing systems in accordance with the prior art, the developer would be required to constantly switch between operating environments associated with the private and collaborative machines in an inefficient and time-consuming series of focus management operations.
Thus, those skilled in the art desire methods and apparatus for implementing a computing environment in which personal and collaborative virtual machines may be simultaneously operative on, and accessed through, a single computing environment. In particular, and most importantly, such a computer system would maintain a strict separation between the operating environments of the private and virtual machines so that changes to the state of either virtual machine would not impact the state of the other virtual machine. This would prevent, for example, a catastrophic failure from propagating from one virtual machine to another.
In addition, those skilled in the art desire that while personal and collaborative virtual machines may be operative on, and accessed through, a single computer system, that access to both the private and collaborative virtual machines be strictly regulated, so only those users with authorization may access the virtual machines. A system operating in this manner would prevent unauthorized users from accessing the virtual machines and changing their states or viewing sensitive information stored within the paradigm of the virtual machines.
Further, those skilled in the art desire a streamlined interface for accessing private and collaborative virtual machines. A system having such an interface would simultaneously display on the interface windows concerning both the private and the collaborative virtual machines. Even more desired is an integrated desktop environment in which applications operative in either one or both the private and virtual machines may be accessed though icons visible in a single desktop. Such a system would provide visual cues to a user indicating in which virtual machine application programs represented by icons on the integrated desktop are operative.